title: Anatomical disruption and length-tension dysfunction of anal sphincter complex muscles in women with fecal incontinence.
abstract: BACKGROUND
  Anal sphincter complex muscles, the internal anal sphincter, external anal sphincter, and puborectalis muscles, play an important role in the anal continence mechanism. Patients with symptoms of fecal incontinence have weak anal sphincter complex muscles; however, their length-tension properties and relationship to anatomical disruption have never been studied.
  
  
  OBJECTIVE
  This study aimed to assess the anatomy of the anal sphincter complex muscles with the use of a 3-dimensional ultrasound imaging system and to determine the relationship between the anatomical defects and the length-tension property of external anal sphincter and puborectalis muscles in women with incontinence symptoms and in control subjects.
  
  
  METHODS
  Severity of anal sphincter muscle damage was determined by static and dynamic 3-dimensional ultrasound imaging. The length-tension property was determined by anal and vaginal pressure with the use of custom-designed probes.
  
  
  METHODS
  Forty-four asymptomatic controls and 24 incontinent patients participated in this study.
  
  
  METHODS
  The anatomical defects and length-tension dysfunction of anal sphincter complex muscles in patients with fecal incontinence were evaluated.
  
  
  RESULTS
  The prevalence of injury to sphincter muscles is significantly greater in the incontinent patients than in the controls. Eighty-five percent of patients but only 9% controls reveal damage to ≥2 of the 3 muscles of the anal sphincter complex. Anal and vaginal squeeze pressures increased with the increase in the probe size (length-tension curve) in the majority of controls. In patients, the increase in anal and vaginal squeeze pressures was either significantly smaller than in controls or it decreased with the increasing probe size (abnormal length-tension).
  
  
  CONCLUSIONS
  We studied patients with severe symptoms. Whether our findings are applicable to patients with mild to moderate symptoms remains to be determined.
  
  
  CONCLUSIONS
  The length-tension property of the external anal sphincter and puborectalis muscles is significantly impaired in incontinent patients. Our findings have therapeutic implications for the treatment of anal incontinence.
authors.affiliation: 1 Department of Medicine, Division of Gastroenterology, San Diego VA Health Care System & University of California, San Diego, California 2 Department of Internal Medicine, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, South Korea.
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Kim
authors.forename: Milena
authors.initials: M
authors.lastname: Weinstein
authors.forename: Varuna
authors.initials: V
authors.lastname: Raizada
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Jiang
authors.forename: Valmik
authors.initials: V
authors.lastname: Bhargava
authors.forename: M Raj
authors.initials: MR
authors.lastname: Rajasekaran
authors.forename: Ravinder K
authors.initials: RK
authors.lastname: Mittal
mesh_terms: D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016022:Case-Control Studies; D005242:Fecal Incontinence / Q000503:physiopathology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008365:Manometry; D008875:Middle Aged; D009130:Muscle, Smooth / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology; D017773:Pelvic Floor / Q000000981:diagnostic imaging / Q000503:physiopathology; D011312:Pressure; D012720:Severity of Illness Index; D014463:Ultrasonography; D014621:Vagina / Q000503:physiopathology